This is a competing continuation application. The overall goals of this longitudinal study are to examine the etiologic determinants as well as the consequences of adult substance use/SUDs. The original sample in 1975 consisted of mothers whose children's average age was 5 (T1). Subsequently, children and their mothers were interviewed when the children's average age was 13 (T2), 15 (T3), and 21 (T4). At T5 and T6, only the young adults were interviewed. A seventh data collection (T7) when the participants are an average age of 37 (and their partners) is proposed to accomplish the following: (1) to examine interrelations and interactions of personality (including psychopathology), family, peer, and ecological factors (starting in early childhood) as they affect the course of substance use/SUDs over time (stability, and change); (2) to study the consequences of long-term substance use on adult psychopathology and functioning; and (3) to examine the impact of substance use/SUDs across generations on parenting and offspring emotional regulation and behavioral problems including substance use. As in the past, separate interviews with adults will be conducted in their own homes by trained interviewers. Scales with adequate psychometric properties measuring the independent variables will be developed from the interview schedules. The primary analytic techniques will be causal analysis, hierarchical or logistic regression analysis, and growth modeling. The significance of this study lies in its in-depth intrapersonal and interpersonal data available at several crucial stages of development. For example, we can examine the pathways to substance use/SUDs from early childhood as well as the course of substance use behavior over time, i.e., the factors related to the subject's becoming more (or less) involved in substance use/SUDs over a span of years. We can also examine the factors related to cessation of use. Such knowledge will help pinpoint those adolescents/young adults at risk for increased substance use/SUDs and will provide detailed and specific guidelines for treatment. Our longitudinal study of the consequences of substance use/SUDs is unique in that the long-term effects of substance use/SUDs can be evaluated to see if their impact is cumulative. Identification of childhood and adolescent factors that can exacerbate the impact of substance use consequences on later adult functioning would provide additional information necessary for effective treatment efforts.